So, at the moment I have two columns in a table, one of which containing a JSON document, like so:
CID:
2
Name:
{"first" : "bob","1" : "william", "2" : "archebuster", "last" : "smith"}
When I do a search on this column using:
SELECT "CID", "Name"->>(json_object_keys("Name")) AS name FROM "Clients" WHERE
"Name"->>'first' LIKE 'bob' GROUP BY "CID";
I get:
CID | name
--------------
2 | bob
2 | william
2 | archebuster
2 | smith
When really I want:
CID | name
2 | bob william archebuster smith
How would i go about doing this? I'm new to JSON in postgresql.
I've tried string_agg and it wouldn't work, presumably because i'm working in a json column, despite the fact '->>' should type set the result to string
UPDATE:
First, you need to understand, if you include a set-returning function into the SELECT clause, you will create an implicit LATERAL CROSS JOIN.
Your query in reality looks like this:
SELECT "CID", "Name"->>"key" AS name
FROM "Clients"
CROSS JOIN LATERAL json_object_keys("Name") AS "foo"("key")
WHERE "Name"->>'first' LIKE 'bob'
GROUP BY "CID", "Name"->>"key"
If you really want to do that, you can apply an aggregate function here (possibly array_agg or string_agg).
SQLFiddle
Related
Sorry, I don't know how to describe that as a title.
With a query (example: Select SELECT PKEY, TRUNC (CREATEDFORMAT), STATISTICS FROM BUSINESS_DATA WHERE STATISTICS LIKE '% business_%'), I can display all data that contains the value "business_xxxxxx".
For example, the data field can have the following content: c01_ad; concierge_beendet; business_start; or also skill_my; pre_initial_markt; business_request; topIntMaster; concierge_start; c01_start;
Is it now possible in a temp-only output the corresponding value in another column?
So the output looks like this, for example?
PKEY | TRUNC(CREATEDFORMAT) | NEW_STATISTICS
1 | 13.06.2020 | business_start
2 | 14.06.2020 | business_request
That means removing everything that does not start with business_xxx? Is this possible in an SQL query? RegEx would not be the right one, I think.
I think you want:
select
pkey,
trunc(createdformat) createddate,
regexp_substr(statistics, 'business_\S*') new_statistics
from business_data
where statistics like '% business_%'
You can also use the following regexp_substr:
SQL> select regexp_substr(str,'business_[^;]+') as result
2 from
3 --sample data
4 (select 'skill_my; pre_initial_markt; business_request; topIntMaster; concierge_start; c01_start;' as str from dual
5 union all
6 select 'c01_ad; concierge_beendet; business_start;' from dual);
RESULT
--------------------------------------------------------------------------------
business_request
business_start
SQL>
I have the following SQL query:
SELECT TOP 3 accounts.username
,COUNT(accounts.username) AS count
FROM relationships
JOIN accounts ON relationships.account = accounts.id
WHERE relationships.following = 4
AND relationships.account IN (
SELECT relationships.following
FROM relationships
WHERE relationships.account = 8
);
I want to return the total count of accounts.username and the first 3 accounts.username (in no particular order). Unfortunately accounts.username and COUNT(accounts.username) cannot coexist. The query works fine removing one of the them. I don't want to send the request twice with different select bodies. The count column could span to 1000+ so I would prefer to calculate it in SQL rather in code.
The current query returns the error Column 'accounts.username' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. which has not led me anywhere and this is different to other questions as I do not want to use the 'group by' clause. Is there a way to do this with FOR JSON AUTO?
The desired output could be:
+-------+----------+
| count | username |
+-------+----------+
| 1551 | simon1 |
| 1551 | simon2 |
| 1551 | simon3 |
+-------+----------+
or
+----------------------------------------------------------------+
| JSON_F52E2B61-18A1-11d1-B105-00805F49916B |
+----------------------------------------------------------------+
| [{"count": 1551, "usernames": ["simon1", "simon2", "simon3"]}] |
+----------------------------------------------------------------+
If you want to display the total count of rows that satisfy the filter conditions (and where username is not null) in an additional column in your resultset, then you could use window functions:
SELECT TOP 3
a.username,
COUNT(a.username) OVER() AS cnt
FROM relationships r
JOIN accounts a ON r.account = a.id
WHERE
r.following = 4
AND EXISTS (
SELECT 1 FROM relationships t1 WHERE r1.account = 8 AND r1.following = r.account
)
;
Side notes:
if username is not nullable, use COUNT(*) rather than COUNT(a.username): this is more efficient since it does not require the database to check every value for nullity
table aliases make the query easier to write, read and maintain
I usually prefer EXISTS over IN (but here this is mostly a matter of taste, as both techniques should work fine for your use case)
Table description
Table Name:- Name condition
Name | Pattern
A | %A% or Name like %a%
B | %B% or Name like %b%
C | %C% or Name like %c%
D | %D% or Name like %d%
E | %E% or Name like %e%
F | %F% or Name like %f%
G | %G% or Name like %g%
Table name:- Employees
Emp_ID | EMP_NAME
1 | Akshay
2 | Akhil
3 | Gautam
4 | Esha
5 | bhavish
6 | Chetan
7 | Arun
[Table description] [1]: https://i.stack.imgur.com/wvOgr.png
Above are my two tables now my query is (in the image)
Select * from Employees,Name_condition where EMP_NAME like Pattern
Here the query is correct syntactically but produces wrong output.
It takes the column Pattern as a string and searches for it in EMP_NAME and it will find nothing.
So my question is how we can take the values present in the Pattern column as a condition and not as a string so that the query will become like this
Select * from Employees,Name_condition where EMP_NAME like ‘%A%’ or Name like ‘%a%’
what i need is when i pass colunm name(Pattern) in the where condition it takes %A% or Name like %a% whole as a string but i want that select * from Employees,Name_condition where EMP_NAME like Pattern Here the column name pattern internally must be replace by the value present in the column and the the query produces o/p like this
Select * from Employees,Name_condition where EMP_NAME like ‘%A%’ or Name like ‘%a%’
Desired Result:-I expect all the rows in my result which includes bhavish but as we see we have a like condition in the column itself like %B% or Name like %b%
What i want is when it matches
where EMP_NAME like Pattern
The value of pattern must internally replaced by
%B% or Name like %b%
and the it produces the output which includes bhavish which starts with b
try:
select *
from employees
where emp_name like '%oh%'
or emp_name like '%a%';
Good luck.
Try this from orafaq:
SELECT * FROM employees
WHERE emp_name LIKE '\%a\%' ESCAPE '\';
It's not that simple (and it shouldn't be). If you really have to use such tables you have to write a piece of PL/SQL to handle your conditions.
Two things you have to read about:
dynamic sql
sql injection (because you want to prevent it)
Try to Put && instead of 'And' in condition
I am not sure how to phrase this question so I'll give an example:
Suppose there is a table called tagged that has two columns: tagger and taggee. What would the SQL query look like to return the taggee(s) that are in multiple rows? That is to say, they have been tagged 2 or more times by any tagger.
I would like a 'generic' SQL query and not something that only works on a specific DBMS.
EDIT: Added "tagged 2 or more times by any tagger."
HAVING can operate on the result of aggregate functions. So if you have data like this:
Row tagger | taggee
--------+----------
1. Joe | Cat
2. Fred | Cat
3. Denise | Dog
4. Joe | Horse
5. Denise | Horse
It sounds like you want Cat, Horse.
To get the taggee's that are in multiple rows, you would execute:
SELECT taggee, count(*) FROM tagged GROUP BY taggee HAVING count(*) > 1
That being said, when you say "select only rows with multiple hits for a specific column", which row do you want? Do you want row 1 for Cat, or row 2?
select distinct t1.taggee from tagged t1 inner join tagged t2
on t1.taggee = t2.taggee and t1.tagger != t2.tagger;
Will give you all the taggees who have been tagged by more than one tagger
I'm very new to SQL and I hope someone can help me with some SQL syntax. I have a database with these tables and fields,
DATA: data_id, person_id, attribute_id, date, value
PERSONS: person_id, parent_id, name
ATTRIBUTES: attribute_id, attribute_type
attribute_type can be "Height" or "Weight"
Question 1
Give a person's "Name", I would like to return a table of "Weight" measurements for each children. Ie: if John has 3 children names Alice, Bob and Carol, then I want a table like this
| date | Alice | Bob | Carol |
I know how to get a long list of children's weights like this:
select d.date,
d.value
from data d,
persons child,
persons parent,
attributes a
where parent.name='John'
and child.parent_id = parent.person_id
and d.attribute_id = a.attribute_id
and a.attribute_type = "Weight';
but I don't know how to create a new table that looks like:
| date | Child 1 name | Child 2 name | ... | Child N name |
Question 2
Also, I would like to select the attributes to be between a certain range.
Question 3
What happens if the dates are not consistent across the children? For example, suppose Alice is 3 years older than Bob, then there's no data for Bob during the first 3 years of Alice's life. How does the database handle this if we request all the data?
1) It might not be so easy. MS SQL Server can PIVOT a table on an axis, but dumping the resultset to an array and sorting there (assuming this is tied to some sort of program) might be the simpler way right now if you're new to SQL.
If you can manage to do it in SQL it still won't be enough info to create a new table, just return the data you'd use to fill it in, so some sort of external manipulation will probably be required. But you can probably just use INSERT INTO [new table] SELECT [...] to fill that new table from your select query, at least.
2) You can join on attributes for each unique attribute:
SELECT [...] FROM data AS d
JOIN persons AS p ON d.person_id = p.person_id
JOIN attributes AS weight ON p.attribute_id = weight.attribute_id
HAVING weight.attribute_type = 'Weight'
JOIN attributes AS height ON p.attribute_id = height.attribute_id
HAVING height.attribute_type = 'Height'
[...]
(The way you're joining in the original query is just shorthand for [INNER] JOIN .. ON, same thing except you'll need the HAVING clause in there)
3) It depends on the type of JOIN you use to match parent/child relationships, and any dates you're filtering on in the WHERE, if I'm reading that right (entirely possible I'm not). I'm not sure quite what you're looking for, or what kind of database you're using, so no good answer. If you're new enough to SQL that you don't know the different kinds of JOINs and what they can do, it's very worthwhile to learn them - they put the R in RDBMS.
when you do a select, you need to specify the exact columns you want. In other words you can't return the Nth child's name. Ie this isn't possible:
1/2/2010 | Child_1_name | Child_2_name | Child_3_name
1/3/2010 | Child_1_name
1/4/2010 | Child_1_name | Child_2_name
Each record needs to have the same amount of columns. So you might be able to make a select that does this:
1/2/2010 | Child_1_name
1/2/2010 | Child_2_name
1/2/2010 | Child_3_name
1/3/2010 | Child_1_name
1/4/2010 | Child_1_name
1/4/2010 | Child_2_name
And then in a report remap it to how you want it displayed